Substituting two daily meals of an energy-restricted diet with meal replacements contributes to weight loss. The Plan is a calorie-controlled diet. Individual results will vary. Healthy weight loss is 1–2 lbs per week. Substituting one daily meal of an energy restricted diet with a meal replacement contributes to the maintenance of weight after weight loss. If you are adolescent, pregnant, breastfeeding, have a medical condition, or want to lose more than 20% of your weight - then talk about your weight loss plans with your doctor or dietician. Slim•Fast meals are not designed to be your only food - add a balanced nutritious meal and healthy snacks every day. Can only help weight loss as part of a calorie controlled diet and an active lifestyle.